SHP2 inhibition displays efficacy as a monotherapy and in combination with JAK2 inhibition in preclinical models of myeloproliferative neoplasms

Garima Pandey 1Lucia Mazzacurati 1Tegan M Rowsell 1Nathan P Horvat 2Narmin E Amin 1Guolin Zhang 3Afua A Akuffo 2Christelle M Colin-Leitzinger 2Eric B Haura 3Andrew T Kuykendall 4Ling Zhang 5Pearlie K Epling-Burnette 2Gary W Reuther 1 4

Abstract

Myeloproliferative neoplasms (MPNs), including polycythemia vera, essential thrombocytosis, and primary myelofibrosis, are clonal hematopoietic neoplasms driven by mutationally activated signaling by the JAK2 tyrosine kinase. Although JAK2 inhibitors can improve MPN patients’ quality of life, they do not induce complete remission as disease-driving cells persistently survive therapy. ERK activation has been highlighted as contributing to JAK2 inhibitor persistent cell survival. As ERK is a component of signaling by activated RAS proteins and by JAK2 activation, we sought to inhibit RAS activation to enhance responses to JAK2 inhibition in preclinical MPN models. We found the SHP2 inhibitor RMC-4550 significantly enhanced growth inhibition of MPN cell lines in combination with the JAK2 inhibitor ruxolitinib, effectively preventing ruxolitinib persistent growth, and the growth and viability of established ruxolitinib persistent cells remained sensitive to SHP2 inhibition. Both SHP2 and JAK2 inhibition diminished cellular RAS-GTP levels, and their concomitant inhibition enhanced ERK inactivation and increased apoptosis. Inhibition of SHP2 inhibited the neoplastic growth of MPN patient hematopoietic progenitor cells and exhibited synergy with ruxolitinib. RMC-4550 antagonized MPN phenotypes and increased survival of an MPN mouse model driven by MPL-W515L. The combination of RMC-4550 and ruxolitinib, which was safe and tolerated in healthy mice, further inhibited disease compared to ruxolitinib monotherapy, including extending survival. Given SHP2 inhibitors are undergoing clinical evaluation in patients with solid tumors, our preclinical findings suggest that SHP2 is a candidate therapeutic target with potential for rapid translation to clinical assessment to improve current targeted therapies for MPN patients.

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Rusfertide Improves Responses in Phlebotomy-Dependent Polycythemia Vera

Caroline Seymour

Patients with phlebotomy-dependent polycythemia vera, a type of myeloproliferative neoplasm, treated with rusfertide experienced a response rate of 60% (n = 18/30) compared with 17% (n = 5/29) in those who received placebo (P = .002), according to updated findings from part 2 of the phase 2 REVIVE trial (NCT04057040) published in the New England Journal of Medicine.1

The international trial was designed with 3 parts: a 28-week, open-label, dose-finding portion in which rusfertide was added to a patient’s ongoing therapy of phlebotomy alone or cytoreductive therapy with optional phlebotomy; a double-blind, randomized withdrawal portion wherein patients were randomly assigned to receive rusfertide or placebo for 12 weeks (weeks 29 to 41); and an open-label extension period following patients on rusfertide therapy for up to 3 years.

Findings from part 1 showed that the estimated mean number of annual phlebotomies was 8.7±2.9 during the 28 weeks before the first dose of rusfertide and 0.6±1.0 during part 1 (estimated difference, 8.1 phlebotomies per year). Moreover, the mean maximum hematocrit level was 44.5±2.2% during part 1 vs 50.0±5.8% during the 28 weeks before the first dose of rusfertide. Patient quality of life was also improved on rusfertide, with a lower severity of disease-related symptoms.

“Rusfertide appears to represent a significant step forward in treating [patients with] polycythemia vera through its unique approach of limiting the amount of iron available for blood cell production,” Marina Kremyanskaya, MD, PhD, an associate professor of medicine (hematology and medical oncology) at Icahn School of Medicine at Mount Sinai in New York, New York, and lead author of the study, stated in a news release.2 “Pending further clinical studies, this injectable agent could become a valuable therapeutic tool for a disease which many patients and their physicians struggle to bring under control.”

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Combination Therapies and New Research Drive Progress in Myelofibrosis

Jordyn Sava

2023 brought a wave of positive developments for patients with myeloproliferative neoplasms (MPNs), particularly myelofibrosis. According to Raajit K. Rampal, MD, PhD, one study of particular interest was the phase 3 MANIFEST-2 trial (NCT04603495) of ruxolitinib (Jakafi) with pelabresib (CPI-0610).

This study, in addition to the TRANSFORM-1 trial (NCT04472598), showed significant improvement in spleen size and potential benefits in symptom reduction with combination therapies compared with single-agent treatments, suggesting that these combinations could become valuable options for treating patients with myelofibrosis upfront.1,2

Other studies, including early data of TP-3654 and selinexor (Xpovio), show potential for further advancements in myelofibrosis treatment.

“There is a lot to be excited about for the first time in a very long time. There are all of these other small molecule inhibitors in clinical trials [and] I think we will learn a lot from that,” said Rampal, hematologic oncologist at Memorial Sloan Kettering Cancer Center, in an interview with Targeted OncologyTM.

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Ryvu Therapeutics to Present Preclinical Data on RVU120 and Synthetic Lethality Programs at the 2024 AACR Annual Meeting

Published: Mar 06, 2024

  • Updated preclinical data will be presented from Ryvu’s synthetic lethality pipeline, including PRMT5 inhibitors in MTAP-Deficient cancers, WRN inhibitors for the treatment of microsatellite unstable (MSI-H) tumors, and Ryvu’s cutting-edge synthetic lethality platform based on primary cancer cells.
  • Poster presentation to highlight the synergistic effects of RVU120 in combination with ruxolitinib in myeloproliferative neoplasms.
  • Ryvu’s partner Menarini to present data on MEN1703 (SEL24), demonstrating promising anti-tumor activity in preclinical models of myelofibrosis both as a single agent and combined with ruxolitinib.

KRAKOW, Poland, March 6, 2024 /PRNewswire/ — Ryvu Therapeutics (WSE: RVU), a clinical-stage drug discovery and development company focusing on novel small molecule therapies that address emerging targets in oncology, announced today that preclinical data from its synthetic lethality pipeline and RVU120 project, as well as on MEN1703 (SEL24), will be presented at the upcoming 2024 AACR Annual Meeting, scheduled for April 5-10 in San Diego, California.

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Years After Genetic Finding, Drugs Targeting CALR-Mutant Myeloproliferative Neoplasms Enter Trials

NEW YORK – More than a decade after mutations in the CALR gene were first linked to the development of myeloproliferative neoplasms, CALR-targeted drug candidates are advancing to Phase I clinical trials.

If these drugs reach the market, they could provide a treatment option for a group of patients with myelofibrosis and essential thrombocythemia who typically must wait until their condition turns serious to attempt a risky stem cell transplant.

About 300,000 patients in the US have myeloproliferative neoplasms. Kapila Vigas, CEO of the MPN Research Foundation, said patients can have very different presentations of the disease, and it can take “years or decades” to get a diagnosis. Although myeloproliferative neoplasms are classified as chronic cancers that patients can live with for many years with blood count monitoring, Vigas said some patients can abruptly progress, and their condition can become serious.

“That uncertainty is really concerning to patients,” Vigas said. “We think from a psychosocial perspective, it’s worse than an acute cancer because while cancer may be more serious, it’s predictable, and there’s a plan and a protocol, whereas when you’re diagnosed with [a myeloproliferative neoplasm] watch and wait is almost a first-line approach. It just adds to the anxiety.”

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Rusfertide More Than Triples Responses Vs Placebo in Phlebotomy-Dependent Polycythemia Vera

Caroline Seymour

Treatment with rusfertide led to a 60% response rate (n = 18/30) vs 17% (n = 5/29) with placebo in patients with phlebotomy-dependent polycythemia vera (P = .002), according to updated findings from part 2 of the phase 2 REVIVE trial (NCT04057040) which were published in the New England Journal of Medicine.1

The international trial was designed with 3 parts: a 28-week, open-label, dose-finding portion in which rusfertide was added to a patient’s ongoing therapy of phlebotomy alone or cytoreductive therapy with optional phlebotomy; a double-blind, randomized withdrawal portion wherein patients were randomly assigned to receive rusfertide or placebo for 12 weeks (weeks 29 to 41); and an open-label extension period following patients on rusfertide therapy for up to 3 years.

Findings from part 1 showed that the estimated mean number of annual phlebotomies was 8.7±2.9 during the 28 weeks before the first dose of rusfertide and 0.6±1.0 during part 1 (estimated difference, 8.1 phlebotomies per year). Moreover, the mean maximum hematocrit level was 44.5±2.2% during part 1 vs 50.0±5.8% during the 28 weeks before the first dose of rusfertide. Patient quality of life was also improved on rusfertide, with a lower severity of disease-related symptoms.

“Rusfertide appears to represent a significant step forward in treating [patients with] polycythemia vera through its unique approach of limiting the amount of iron available for blood cell production,” Marina Kremyanskaya, MD, PhD, an associate professor of medicine (hematology and medical oncology) at Icahn School of Medicine at Mount Sinai in New York, New York, and lead author of the study, stated in a news release.2 “Pending further clinical studies, this injectable agent could become a valuable therapeutic tool for a disease which many patients and their physicians struggle to bring under control.”

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Addition of Parsaclisib to Ruxolitinib Decreases Spleen Volume and Improves Symptom Scores Among Patients With Myelofibrosis

Jordan Kadish

02/23/2024

The addition of parsaclisib to stable-dose ruxolitinib treatment decreased spleen volume, improved symptom scores, and yielded acceptable safety among patients with primary or secondary myelofibrosis (MF), according to findings from a phase 2 trial published in Blood Advances.

Abdulraheem Yacoub, MD, The University of Kansas Cancer Center, Kansas City, Kansas, and coauthors explained that although ruxolitinib has demonstrated beneficial results among patients with intermediate- or high-risk myelofibrosis, “suboptimal response may occur, potentially because of signaling via the phosphoinositide 3-kinase (PI3K)/protein kinase B pathway.”

In this phase 2 trial, the study authors aimed to measure the potential benefit of adding PI3Kδ inhibitor parsaclisib to ruxolitinib treatment among patients with primary or secondary myelofibrosis who did not have optimal responses to ruxolitinib alone. The primary end points were dosing, efficacy, and safety of this treatment combination.

All patients included in this study stayed on a stable dose of ruxolitinib. Among these patients, 32 were administered parsaclisib at 10 or 20 mg once daily for 8 weeks, then once weekly afterward (daily-to-weekly dosing). Additionally, 42 patients were administered parsaclisib at 5 or 20 mg once daily for 8 weeks, and then 5 mg once daily afterward (all-daily dosing).

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Study shows early success of a novel drug in treating a rare and chronic blood cancer

February 21, 2024

by The Mount Sinai Hospital

A novel treatment for polycythemia vera, a potentially fatal blood cancer, demonstrated the ability to control overproduction of red blood cells, the hallmark of this malignancy and many of its debilitating symptoms in a multi-center clinical trial led by the Icahn School of Medicine at Mount Sinai.

In the phase 2 study, the drug rusfertide limited excess production of red blood cells, the main manifestation of polycythemia vera, over the 28-week course of treatment. The results suggest it could replace therapeutic phlebotomy, a common form of treatment which has proven to be a burden for many patients. The results of the study were published today (Feb. 21) in The New England Journal of Medicine.

“Rusfertide appears to represent a significant step forward in treating polycythemia vera through its unique approach of limiting the amount of iron available for blood cell production,” says Marina Kremyanskaya, MD, Ph.D., Associate Professor of Medicine (Hematology and Medical Oncology) at Icahn Mount Sinai and lead author of the study.

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JNJ-88549968 by Johnson & Johnson for Essential Thrombocythemia: Likelihood of Approval

JNJ-88549968 is under clinical development by Johnson & Johnson and currently in Phase I for Essential Thrombocythemia. According to GlobalData, Phase I drugs for Essential Thrombocythemia does not have sufficient historical data to build an indication benchmark PTSR for Phase I. GlobalData uses proprietary data and analytics to create drugs-specific PTSR and LoA in the JNJ-88549968 LoA Report. 

GlobalData tracks drug-specific phase transition and likelihood of approval scores, in addition to indication benchmarks based off 18 years of historical drug development data. Attributes of the drug, company and its clinical trials play a fundamental role in drug-specific PTSR and likelihood of approval.

JNJ-88549968 overview

JNJ-88549968 is under development for the treatment of calreticulin (CALR)-mutated myeloproliferative neoplasms, essential thrombocythemia, neoplasms, leukemia and myelofibrosis. The therapeutic candidate is a bispecific antibody acts by targeting calreticulin and CD3.

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Disc wins orphan drug tag for rare blood cancer

February 12, 2024

By Jeanne Philpott

The US Food and Drug Administration (FDA) has granted an orphan drug designation (ODD) to US-based biotech Disc Medicine’s DISC-3405 to treat rare blood cancer polycythemia vera (PV).

Disc gained exclusive rights to develop and market the anti-TMPRSS6 (Transmembrane Serine Protease 6) humanized antibody in the US and other territories when it teamed up with Mabwell Therapeutics in a $412.5m licensing agreement in January 2023.

In October 2023, DISC initiated an ongoing Phase I clinical trial (NCT06050915) for DISC-3405, previously named MWTX-003 with data from the study now expected in H1 2024. The orphan drug designation comes after the drug had previously received fast-track designation from the FDA.

The 64-patient Phase I study is divided into groups receiving either a single or multiple doses of DISC-3405, or a placebo. In the single ascending dose (SAD) phase, two subjects serve as sentinels: one receives DISC-3405, and the other placebo. Additional subjects in the cohort are dosed at least 24 hours after the last sentinel dosing, following approval from the principal investigator. Subsequent multiple ascending dose (MAD) cohorts are enrolled only after a sufficient safety observation period for the SAD cohort, removing the need for sentinels in MAD cohorts.

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